This invention relates to glucose monitoring, and more particularly, to glucose level monitoring using laser-induced emission spectroscopy.
Millions of people, afflicted with diabetes, must periodically monitor their blood glucose level because their bodies are unable to maintain a constant blood glucose level without diet adjustments and periodic insulin injections. Most popular methods for monitoring blood glucose levels require a small blood sample that is periodically drawn from the body for analysis.
Recently, noninvasive optical techniques have been developed to monitor the blood's glucose level using infrared absorption through a portion of the body. However, infrared absorption techniques are susceptible to accuracy problems, in part because glucose has more than 20 infrared absorption peaks, many of which overlap with the absorption peaks of other constituents in the body.
Fluorescence spectroscopy using ultraviolet (UV) excitation light has been introduced for monitoring glucose levels. This technique requires, among other things, the monitoring of a spectral peak within the induced fluorescence spectrum. Accurately locating the peak may be difficult for a low-level fluorescence signal in the presence of noise. Increasing the intensity of the excitation light may not be a desirable option because of concerns of UV exposure to the body. Also, known fluorescence spectroscopic techniques generally fail to take full advantage of information contained in the fluorescence spectrum at wavelengths other than the peak wavelength and fail to account for certain nonlinear relationships between the glucose level and the resulting emission spectra.
From the discussion above, it should be apparent that there is a need for an apparatus, and related method, for monitoring glucose that is simple and rapid to use, and that provides good accuracy in spite of nonlinearities or low signal-to-noise levels. The present invention fulfills these needs.